A Review Of Landscape Development And Erosion Cycles In Southern Africa

Author : Christian Sommer
Publisher :
ISBN 13 :
Total Pages : 0 pages
Book Rating : 4.:/5 (129 download)

DOWNLOAD NOW!

Download or read book Reconstruction of the Pleistocene Landscape of Southern KwaZulu-Natal, South Africa by Means of GIS, Remote Sensing and Geomorphological Techniques written by Christian Sommer and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Eastern South Africa, and particularly the region around Sibudu Cave, plays an important role in the history of Homo sapiens. The Middle Stone Age is characterized by technological innovation, population dynamics, and complex symbolic and social behavior, but also by spatial and temporal variability (Will et al., 2019). These are attempted to be explained by diverse hypotheses, most of which consider Late Pleistocene environmental change. For this reason, paleoenvironmental research provides an important contribution to building a picture of the lifestyle of early humans. Thus, in addition to archaeological research, highly recognized knowledge of paleoclimate, vegetation, and fauna has been obtained at Sibudu Cave for decades. This dissertation provides a contribution to the geomorphological evolution of the region, the landscape forms and processes contained therein. For this purpose, several landscape elements were studied in two study areas: The Tongati Valley, representing the immediate environment of the prehistoric people, and the Upper Umkomazi Valley at the foot of the Drakensberg, where supra-regional environmental influences were assessed. Methodologically, the work covers a wide range and includes topics from GIS analysis, remote sensing, and geomorphological field work. In each case, tailored solutions to the issues have been developed, such as 3D modeling, object-based image analysis, simulation, geomorphometry, etc. The analysis of the Masotcheni Formation using electromagnetic spectroscopy can also be considered innovative. The results show that the Tongati River valley was formed by the African, Post-African I, and Post-African II landscape cycles, and thus is the result of tectonic uplift and tilting, as can be reconstructed based on planation surfaces. Due to the complex geology, the evolution of the drainage system proceeded in a differentiated manner such that the middle reaches upstream of Sibudu Cave continuously deepened into the hard lithology but did not reach hydrologic equilibrium, while the lower reaches dynamically adapted to Pleistocene sea level lowstands, as evidenced by several terrace generations and an alluvially filled estuary. Late Pleistocene sea level fluctuations also resulted in coastal plain expansion of up to 5500 km2 and coastal regression, such that Sibudu Cave was located up to over 30 km inland. This has relevance for the interpretation of procurement of marine resources and the use of space by Sibudu's earlier occupants. The Masotcheni Formation in the Drakensberg indicates late Pleistocene landscape stability cycles that are largely consistent with those formulated by Botha (1996). According to this, one type of soils developed under humid influences in the late MIS4 / early MIS 3, while another type of soils developed under semi-arid conditions after the middle MIS 3. These phases are interrupted by periods of increased erosion and deposition. Analyses of recent gully erosion revealed that the origin of this erosional form in the Masotcheni sediments can be approximated to have initiated around the Little Ice Age and concurrent population and land use changes in the mid-17th century. The high erosion rates under modern climatic conditions explain why sediments deposited prior to MIS 5e, which has a similar climate, are very rare. It can be summarized that the region was subject to strong landscape changes in the late Pleistocene, and the ability to deal with this variable environment requires a high level of social and cognitive skills.